The instant invention is directed to a hand tool which operates to separate drum brake shoes which are held in position by springs. The tool acts to separate the shoes a distance sufficient to disconnect them from the brake cylinder while remaining connected with the braking system.
There have been numerous tools produced which are adapted to spread disk brake pads for replacing the pads or for positioning the pads. U.S. Pat. Nos. 3,727,490; 3,835,522; 4,086,828; 4,809,567; and 5,018,261 each show a device designed to separate disk brake calipers.
There also have been hand tools created to engage and separate opposed drum brake shoes in order to free the automatically adjustable spacer. These tools comprise straight arms pivotally connected and adapted to engage and wedge apart opposed ends of the drum brake shoes. U.S. Pat. Nos. 4,768,408 and 5,165,312 show embodiments of their type of hand tools.
The present invention has, as an object, the method of separating opposed and spring biased drum brake shoes from engagement with a brake cylinder while maintaining the shoes in a biased connection with the brake system. The method includes providing a spreading tool having a pair of depending forks which are arranged to move relative to each other along a longitudinal shaft and positioning the forks in substantially adjacent relation. Engaging end portions of each of the opposed brake shoes with a respective of the forks and causing the forks and engaged brake shoes to move in diverging directions a distance along the shaft sufficient to separate the brake shoes from the brake cylinder.
The invention further has for its object a tool operable to separate spring biased drum brake shoes from a brake cylinder while maintaining the brake shoes in spring biased connection in a brake system. The tool includes a threaded bolt having a head at one end, a bearing formed adjacent the head, a first fork having downwardly depending prongs mounted with the bearing for rotation about the bolt in fixed longitudinal relation with the bolt, and a second fork having downwardly depending prongs mounted in mating contact with the threads of the bolt for longitudinal movement there along. Each fork is outwardly bowed, and is approximately 2" in length, 1" in width and 7/64" in thickness. The prongs are at least 1/4" long and are spaced by at least 15/32". The bolt includes a 3/8" threaded rod which is between 8" and 12" long.
The bearing is defined by the head and a lock nut longitudinally spaced from the head in fixed position on the bolt. A pair of washers may be positioned separate the first fork from the head and nut.
The second fork includes an aperture and a threaded nut aligned with the aperture and fixed with the fork. The threads of the nut mate with the threads of the bolt.
The two brake shoes of the brake system are arranged in opposed relationship. Each brake shoe is structured to include a spine and a pad support surface. The prongs of each fork are designed to extend along opposite sides of the spine of each brake shoe in position to engage with an edge of the pad support surface. Diverging movement of the forks moves the brake shoes outwardly and away from the cylinder. This movement is done without disconnecting the spring biased connection which maintains the brake shoes within the braking system.
The primary object of the present invention is to provide a tool which facilitates replacement or repair of the brake cylinder with a time saving of at least on hour.
Another object of the invention is the provision of a tool which provides access to the brake cylinder of a drum brake system without disconnecting the brake shoes and their retaining springs.
Another object of the invention is a tool which operates to separate drum brake shoes from the brake cylinder.
Another object of the invention is the provision of a spreading tool which may be connected with a power tool to be driven thereby.
Another object of the invention is a drum brake shoe spreader tool which is capable of functioning with substantially all known types of drum brake systems of automobiles, trucks, trailers, etc.